Feeding of powder or other fluent materials of substantially equal quantities



Apral 21, 1959 J. A. KAY 2,882,938

FEEDING 0F POWDER OR OTHER FLUENT MATERIALS 0F SUBSTANTIALLY EQUALQUANTITIES Filed Jan. 7. 1957 FIGZ.

Inventor :JHMES HR mun K HY y 3 mm q. gwumttameys United States PatentFEEDING OF POWDER OR OTHER FLUENT MA- gTRgLs OF SUBSTANTIALLY EQUALQUAN- James Arthur Kay, Gainsborough, England, assignor to Rose Brothers(Gainsborough) Limited, Gainsborough, England, avBritish companyApplication January 7, 1957, Serial No. 632,936

Claims priority, application Great Britain January 11, 1956 5 Claims.(Cl. 141-132) This invention relates to the feeding of powder or otherfluent material such as, for example, granulated, flaky or othercomminuted materials, in substantially equal quantities. Such materialswill 'be referred to herein simply as powder. The invention isparticularly concerned with the feeding of powder in a continuoussubstantially uniform stream towards a series of delivery funnels whichare moved in succession through the stream in such a .manner that eachreceives the stream for substantially the same pre-determined period,the powder then passing from each funnel into a container movable inregister with each funnel while it passes through the stream. Providedthat the stream of powder flows at a substantially constant rate,therefore, each container receives substantially the same pre-determinedquantity of powder by volume.

It is sometimes found, however, that whilst the quantities received bythe successive containers are substantially equal by volume, the weightof the volume changes from time to time for a variety of reasonsdepending to some extent on the kind of powder being fed. Thus, powderof a given kind may vary in density by reason of atmospheric changes orby variation in the size of the individual particles making up thepowder; or again by the degree of aeration given to the powder byturbulence during the feeding operation.

An object of the invention is to vary the rate of flow of the stream ofpowder in accordance with variation in the density of the powder so thatthe quantities received by the containers will be substantially equal inweight.

According to the present invention, powder .is continuously fed in astream at a pro-determined rate towards the containers, the stream:being arranged to impinge on a vane carried by a pivoted arm so as tocause that arm to tend to rotate about its pivot, the arm beingyieldably pre-loaded against such rotation by an amount sufiicientsubstantially to balance the load applied to the vane by .thepre-determined rate of flow of the powder, and means responsive to anysensible movement of the ivoted arm from its normal position of balanceare provided for varying the rate of flow of the stream to restore thebalance.

The stream of powder is conveniently produced by an electro-magneticvibrating feed device of .known kind, the speed of operation of thedevice (and thus the rate of flow of the powder) being controlled by anelectrical control unit. With such construction, the means for varyingthe rate of flow may consist of an air-operated two way switch wired inthe circuit of the control unit, the switch being under the control ofan air-controller of the Solex type having an air jet impinging on anarcuate surface mounted on the vane-carrying arm, the surface beingdisposed eccentrically with respect to the pivotal axis of the arm sothat pivotal movement of the arm varies the gap between the jet and thesurface, thus producing the differential pressure for operating theswitch.

The stream of powder conveniently falls down a chute 2,882,938 PatentedApr. 21, 19,59

the discharge end of Whichis arranged above the path of movement of aseries of delivery funnels carried by a rotatable drum, the dischargeoutlets from the delivery funnels, in turn being arranged above the pathof movement of a series of cartons carried by a conveyor so arrangedthat each cartonrnoves into register with a funnel before that funnelpasses the chute.

To provide for variation in the speed of operation of the apparatuswhile maintaining the same quantity of powder in the cartons,.means maybe provided for automatically varying the amount of pre-loading of thevanecarrying arm in proportion .to the variation in speed of theapparatus, so as to maintain the normal balance of the arm in spite ofvariation in the rate of fiow of powder necessary for different speedsof operation of the apparatus.

By way of example, the invention will now be described in greater detailwith reference to the accompanying drawings, as applied to an apparatusfor packaging powder in cartons.

In the drawings:

Figure 1 represents diagrammatically such an apparatus, and 9 Figure 2is an end view of the apparatus.

In general, powder is fed from a main feed pipe 11 into a tray 12 ofchannel section which is vibrated by an electro-magnetic vibratory feeddevice 13 of known construction, the rate of operation of the devicebeing variable by an electrical control unit 14. The tray 12 dischargesa stream of powder into a chute 15 arranged above a rotatable carriermember 17 on the peripherylof which is arranged a series of continuousdischarge funnels 18 the upper edges of which are sufficiently sharp toavoid powder accumulating on the edges. The chute 16 is so arranged thateach discharge funnel 18 passes in turn below the outlet of thechute.

Below the carrier member 17 is arranged a chain conveyor 19 carrying aspaced succession of cartons 21, the conveyor 19 guiding the successivecartons 21 into register with successive funnels 18 and maintaining themin such registration over about 180 of the movement of the carriermember 17. In this manner, each carton 21 receives the stream forsubstantially the same pre determined period, and assuming uniformity offlow, therefore, each carton receives substantially the samepredetermined quantity of powder by volume.

Freely pivoted at 22 in anti-friction bearings is an arm 23 carrying avane 24 passing into the chute 16 and extending transversely into thepath of movement of the stream. The channel 12 discharges into a tube 26of smaller diameter than the width of the vane 24, and the adjacent edgeof the tube 26 acts as a limit stop for the vane 24, the latter beingyieldably urged towards the stop by a plunger 27 slidably mounted in ahousing 28 and urged into contact with the arm 23 by a spring containedwithin the housing 28. The spring prevlo-ads the vane 24 against pivotalmovement under the influence of the stream, the amount of pre-loadingbeing suflicient substantially to balance the load applied to the vane24 by the pre-determined rate of flow of the powder.

The arm 23 is provided with a curved'surface 29 eccentric to the pivot22, and there is arranged adjacent the surface 29 .a nozzle 31 fromwhich an air jet is arranged to impinge on the surface. The nozzle 31 isprovided with compressed air at a normally constant pressure by anair-controller 32 of the type well known under the name Solex, air atthe same pressure passing through a branch 33 to a chamber 34 housing atwo-Way control switch 36 operable by a spring loaded diaphragm 37, theswitch being connected in the circuit of the control unit 14.

It will thus be seen that pivotal movement of the arm 23 causes avariation in the gap between the nozzle 31 and the surface 29 thuscausing a variation in the pressure of the air entering the chamber 34,with the result that the switch is actuated by the diaphragm one way orthe other to operate thecontrol unit 14 to vary the rate of operation ofthe vibratorydevice 13.

With the vane arm 24 pre-loaded to suit the rate of flow of powdernecessary to provide a given quantity in the cartons 21, therefore, itwill be seen that any sensible change in the density of the powder willcause pivotal movement of the vane 24 in one direction or the otheraccording as the powder is heavier or lighter than normal, such movementof the vane 24 varying the air gap mentioned above to operate the switch34 one way or the other to decrease or increase the rate of feed of thepowder by the feed device 13 as the case may :be. In this manner,variation in the weight of the powder fed to successive cartons 21 canbe maintained between tolerable limits.

To provide for variation in the speed of operation of the apparatuswhile maintaining the same quantity of powder in the cartons, the amountof pre-loading of the arm 23 is automatically varied in proportion tothe variation in speed of the apparatus. This is brought about in thepresent example by the provision of a pilot motor 38 connected bygearing 39 to a screw device within the housing 28 for increasing ordecreasing the tension on the spring urging the plunger 27 intoengagement with the arm 23. The motor 38 is identical with and connectedin the circuit of the pilot motor 41 operating avariable speed mainmotor 42 for driving the apparatus. Any change in the desired speed ofoperation of the apparatus, therefore, immediately produces acorresponding change in the pro-loading of the vane 24 so as to maintainthe normal balance of the vane in spite of the necessary change in therate of flow of the powder.

I claim:

1. Packaging apparatus for feeding successive predetermined quantitiesof powder to successive containers in which the powder is fed in acontinuous stream at a controlled rate towards a delivery stationthrough which the containers pass in succession, said apparatuscomprising a vane carried by a pivoted arm and so arranged that thestream will impinge on the vane so as to cause that arm to tend torotate about its pivot, means for yieldably preloading the arm againstsuch rotation by an amount sufiicient substantially to balance the loadapplied to the vane by the predetermined rate of flow of the powder,means responsive to any sensible movement of the pivoted 'arm from itsnormal position of balance for varying the rate of flow of the stream torestore the balance, forwarding means for moving the containers throughthe stream, and means responsive to variation in the speed of theforwarding means for varying the pre-loading of the vane-carrying arm inthe direction and in the amount so that the quantity of powder fed tothe successive containers is substantially constant.

2. Packaging apparatus for feeding successive predetermined quantitiesof powder to successive containers in which the powder is fed in acontinuous stream at a controlled r-ate towards a delivery stationthrough which the containers pass in succession, said apparatuscomprising an electro-magnetic vibratory feed device provided withcontrol means for varying its rate of operation, a vane carried by apivoted arm and so arranged that the stream '4 will impinge on the. vaneso as to cause that arm to tend to rotate about its pivot, means foryieldably pre-loading the arm against such rotation by an amountsufiicient substantially to balance the-load applied to the vane by thepre-determined rate of flow of the powder, means responsive to anysensible movement of the pivoted arm from its normal position of balancefor operating the control means to vary the rate of operation of thefeed device, and thus the rate of flow of the stream, to restore thebalance, forwarding means for moving the containers through the stream,and means responsive to variation in the speed of the forwarding meansfor varying the preloading of the vane-carrying arm in the direction andin the amount so that the quantity of powder fed to the successivecontainers is substantially constant.

3. Apparatus as in claim 2, comprising an air-operated two way switchwired in the circuit of the control means, an arcuate surface disposedon the pivoted arm eccentrically with respect to its pivotal axis, anozzle disposed adjacent said surface and adapted to cause a jet ofcompressed air to impinge on the surface, an air connection between thenozzle and the switch, pivotal movement of the arm thus varying the gapbetween the nozzle and the surface to vary the pressure of the aircommunicated to the switch.

4. Apparatus as in claim 1, comprising a chute into which the stream isdirected, a series of delivery funnels carried by a rotatable drum, thedischarge outlet of the chute being arranged above the path of movementof the delivery funnels, and a conveyor adapted to forward a series ofcartons in such a manner that each carton moves into register with afunnel before that funnel passes the chute.

5. Packaging apparatus for feeding successive predetermined quantitiesof powder to successive containers in which the powder is fed in acontinuous stream at a controlled rate towards a delivery stationthrough which the containers pass in succession, said apparatuscomprising a vane carried by a pivoted arm and so arranged that thestream will impinge on the vane so as to cause that arm to tend torotate about its pivot, means for yieldably pre-loading that arm againstsuch rotation by an amount suflicient substantially to balance the loadapplied to the vane by the predetermined rate of flow of the powder,means responsive to any sensible movement of the pivoted arm from itsnormal position of balance for varying the rate of flow of the stream torestore the balance, forwarding means for moving the containers throughthe stream, spring means responsive to variation in the speed of theforwarding means for varying the preloading of the vane-carrying arm, ascrew device for varying the tension in the spring means, a pilot motorconnected by gearing to the screw device, an identical motor wired inthe circuit of the pilot motor and adapted to operate a vairable speedmain motor for driving the machine.

References Cited in the file of this patent UNITED STATES PATENTS764,705 Bousser July 12, 1904 1,558,668 Carter Oct. 27, 1925 2,273,330Robinson Feb. 17, 1942 2,513,215 Strehlow June 27, 1950

